#ifndef  __ARM_DIV64_H__
#define  __ARM_DIV64_H__

#include <types.h>

/*
 * The semantics of do_div() are:
 *
 * uint32_t do_div(uint64_t *n, uint32_t base)
 * {
 *      uint32_t remainder = *n % base;
 *      *n = *n / base;
 *      return remainder;
 * }
 *
 * In other words, a 64-bit dividend with a 32-bit divisor producing
 * a 64-bit result and a 32-bit remainder.  To accomplish this optimally
 * we call a special __do_div64 helper with completely non standard
 * calling convention for arguments and results (beware).
 */

#ifdef __ARMEB__
#define __xh "r0"
#define __xl "r1"
#else
#define __xl "r0"
#define __xh "r1"
#endif

#define __asmeq(x, y)  ".ifnc " x "," y " ; .err ; .endif\n\t"

#define __do_div_asm(n, base)                                   \
({                                                              \
        register unsigned int __base      asm("r4") =base;     \
        register unsigned long long __n   asm("r0") = n;        \
        register unsigned long long __res asm("r2");            \
        register unsigned int __rem       asm(__xh);            \
        asm(    __asmeq("%0", __xh)                             \
                __asmeq("%1", "r2")                             \
                __asmeq("%2", "r0")                             \
                __asmeq("%3", "r4")                             \
                "bl     __do_div64"                             \
                : "=r" (__rem), "=r" (__res)                    \
                : "r" (__n), "r" (__base)                       \
                : "ip", "lr", "cc");                            \
        n = __res;                                              \
        __rem;                                                  \
})

#define do_div(n, base) __do_div_asm(n, base)

#endif /* !__ARM_DIV64_H__ */
